KR102004825B1 - Non-conductive paste for chip bonding using the solder bump and method of chip bonding using the same - Google Patents

Abstract

The present invention relates to a nonconductive paste composition comprising an epoxy resin, a hardener, an activator, a curing accelerator, and a filler, and more particularly, It is possible to provide a nonconductive paste composition which can be used in general in a bonding method and can be carried out by integrating various processes of a bonding process.

Description

[0001] The present invention relates to a non-conductive paste composition for chip bonding using a solder bump,

The present invention relates to a nonconductive paste composition for chip bonding using a solder bump and a chip bonding method using the composition. More specifically, the present invention can be applied to both thermal bonding bonding and laser bonding methods, To a non-conductive paste composition.

BACKGROUND ART [0002] As the electronic industry in recent years has become lighter, smaller, faster, multifunctional, and more sophisticated, there has been a demand for a technique for manufacturing products with higher reliability at a lower cost. One of the important technologies for realizing such requirements is package technology, and adhesive research for fine pitch interconnection is being conducted.

A method of connecting a semiconductor chip using a nonconductive adhesive directly to a printed circuit board is usually a semiconductor chip mounted on a printed circuit board (PCB) through a reflow soldering process. The bonding method uses thermal compression bonding or laser bonding. Since the curing method of the solder paste is different according to the bonding method, solder paste of different composition is used for each bonding method.

Meanwhile, the conventional printed circuit board is coated with an organic solderability preservative (OSP) to prevent oxidization or contamination of electrodes generated in the process. This coating requires a separate fluxing process to remove the OSP material, since the coating must be removed before the interconnect with the semiconductor chip on which the solder bump is formed is formed. Oxides and impurities may be generated on the surface of the solder formed of the metal even when the OSP process is not performed. This also causes a connection failure when the semiconductor chip is connected to the semiconductor chip. Therefore, a fluxing process using a flux is performed separately have. This fluxing process requires equipment, cost and time to remove (fusion, incineration, etc.) OSP materials, oxides and impurities.

When ready for bonding after fluxing, a solder paste is printed on the PCB using a dispenser, the semiconductor chip with solder bumps is contacted and heated to reflow the solder paste and solder, An electrical interconnect is formed. Heating can be facilitated, for example, by exposure to infrared light of a solder paste or by heating in an oven.

The solder paste can also be used as an underfill application as an adhesive material, but in order to improve the adhesive strength, a process of processing with separate under fill materials which substantially fill the area between the semiconductor chip and the PCB is added More equipment, cost and time are required.

Accordingly, it is an object of the present invention to provide a nonconductive paste composition which can be widely used in various bonding methods in chip bonding using a solder bump, and can be integrated with various processes of the bonding process.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a nonconductive paste composition for chip bonding using solder bumps, which can be widely used for various bonding methods, To provide a nonconductive paste composition.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

The present invention relates to an epoxy resin comprising at least two selected from the group consisting of bisphenol A type, bisphenol F type, aliphatic polyglycidyl type, phenol novolac type and cresol novolac type epoxy; An amine, an amine-modified latent curing agent, an imidazole-based curing agent, a polyphenol-based curing agent and an acid anhydride curing agent; An active agent comprising at least one member selected from the group consisting of propionic acid, adipic acid, succinic acid, palmitic acid, tetraheptanoic acid and dimethylpropionic acid; A curing accelerator comprising at least one member selected from the group consisting of tertiary amine salts, acid anhydrides containing accelerators, and dicyandiamide; And a filler comprising at least one selected from the group consisting of SiO ₂ , TiO ₂ , AlO ₂ , AlO ₃ , Silicon Carbide, and Boron Nitride.

The curing accelerator is contained in an amount of 90 to 100 parts by weight based on 100 parts by weight of the epoxy resin, 20 to 40 parts by weight of the activator, 1 to 4 parts by weight of the curing accelerator, and 140 to 170 parts by weight of the filler .

The epoxy resin may include any three or more selected from the group consisting of a bisphenol A type, a bisphenol F type, an aliphatic polyglycidyl type, a phenol novolac type, and a cresol novolac type do.

The epoxy resin is characterized by containing 40 to 60% by weight of aliphatic polyglycidyl, 20 to 30% by weight of bisphenol F type and phenol novolak type, respectively.

The curing agent may be any one selected from the group consisting of an amine, an amine-modified latent curing agent, an imidazole-based resin, a polyphenol-based resin, and an acid anhydride curing agent.

Also, the curing agent is characterized by comprising 80 to 90% by weight of an acid anhydride-based curing agent, 1 to 5% by weight of an amine-modified latent curing agent, and 10 to 15% by weight of polyphenol.

In addition, the filler is an average particle diameter of 0.5 to 2μm, it characterized in that it comprises a mixture of 80-90% by weight of SiO _2, Boron Nitride 10 to 20% by weight.

The nonconductive paste composition may further comprise at least one kind of thisxotropic agent selected from the group consisting of Wax, Thixo ST, Glycol Powder and Powder Type Epoxy Resin in an amount of 0.5 to 4 parts by weight per 100 parts by weight of the epoxy resin And further comprising:

Further, the nonconductive paste composition is cured by a thermal compression method to bond semiconductor chips to a printed circuit board.

The nonconductive paste composition may be cured by a laser method to bond the printed circuit board to a semiconductor chip.

The present invention can provide a nonconductive paste composition that can be used in various bonding methods in chip bonding using solder bumps, and can be integrated with various processes of the bonding process.

In addition, the present invention can dramatically reduce equipment, cost, and time required for the bonding process by using the nonconductive paste composition, and can be used for thermo-compression bonding and laser bonding, It is possible to provide a nonconductive paste composition which is easy to design.

1 is a schematic view of a bonding method using a nonconductive paste composition according to an embodiment of the present invention.
FIG. 2 is a view showing a chip rotation experiment judgment criterion of a package bonded using a nonconductive paste composition according to an embodiment of the present invention.
FIG. 3 is a photograph of the laser-bonded package using the nonconductive paste composition according to an embodiment of the present invention.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout this specification and claims, the word "comprise", "comprises", "comprising" means including a stated article, step or group of articles, and steps, , Step, or group of objects, or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. Any feature that is specifically or advantageously indicated as being advantageous may be combined with any other feature or feature that is indicated as being preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

The nonconductive paste composition according to an embodiment of the present invention includes an epoxy resin, a hardener, an activator, a curing accelerator, and a filler.

The epoxy resin preferably comprises any two or more selected from the group consisting of bisphenol A type, bisphenol F type, aliphatic polyglycidyl type, phenol novolak type and cresol novolak, It is preferable to include any three or more selected from the group consisting of bisphenol A type, bisphenol F type, aliphatic polyglycidyl type, phenol novolac type and cresol novolak.

When three or more epoxy resins are used in combination, 40 to 60% by weight of aliphatic polyglycidyl, 20 to 30% by weight of bisphenol F type and phenol novolak type, and bisphenol A type 5 to 10% by weight.

The epoxy resin may be selected from the group consisting of methyl ethyl ketone (MEK), demethylformamide (DMF), methylcellosolve (MCS), carbitol acetate, carbitol, PGMEA, PGME, toluene, xylene, NMP, And the like can be mixed and dissolved as a solvent.

The hardener includes at least one selected from the group consisting of amine, amine-modified latent curing agent (trivalent amine and the like), imidazole-based, polyphenol-based and acid anhydride curing agent. It is preferable to include at least two selected from the group consisting of amine, amine-modified latent curing agent (trivalent amine and the like), imidazole-based, polyphenol-based and acid anhydride curing agent, , Amine-modified latent curing agents (such as trivalent amines), imidazole-based, polyphenol-based, and acid anhydride curing agents.

(THPA, ME-THPA, HHPA, etc.) in an amount of 80 to 90% by weight and an amine-modified latent curing agent (such as MY-24 and PN-23) It is preferable to mix 1 to 5% by weight of polyphenol with 10 to 15% by weight of polyphenol as a substance which participates in curing at a specific temperature (80 to 120 ° C).

The curing agent may be included in an amount of 90 to 100 parts by weight based on 100 parts by weight of the epoxy resin. If the content of the curing agent is less than 90 parts by weight, there is a problem that the resin is hardly cured and may be easily broken or the strength may be weak. When the content of the curing agent is more than 100 parts by weight, There is a problem that it adversely affects other reliability evaluations.

The activator may be included in the composition to facilitate the removal of the oxide and to help cure the resin. Examples of the activator include propionic acid, adipic acid, succinic acid, palmitic acid, tetra teicanoic acid, and dimethylpropionic acid And the like. It is preferable to use at least one selected from the group consisting of propionic acid, adipic acid, succinic acid and dimethylpropionic acid, more preferably dimethyl propionic acid.

The activator is included in an amount of 20 to 40 parts by weight based on 100 parts by weight of the epoxy resin. If the content of the activator is less than 20 parts by weight, removal of the oxide film is not easy and the soldering property is deteriorated. If the amount of the activator is more than 40 parts by weight, the resin hardening state becomes low. Preferably 20 to 30 parts by weight.

The curing accelerator includes at least one selected from the group consisting of a tertiary amine salt, an acid anhydride containing an accelerator, and dicyandiamide. Preferably, the use of DA having a double bond as an acid anhydride containing an accelerator is preferable because it has a good heat-generating property at 90 to 110 캜 and shortens the curing time. The curing accelerator is preferably contained in 1 to 4 parts by weight, more preferably 1 to 3 parts by weight, based on 100 parts by weight of the epoxy resin.

The filler includes at least one selected from the group consisting of SiO ₂ , TiO ₂ , AlO ₂ , AlO ₃ , Silicon Carbide, and Boron Nitride.

The filler may be in the form of particles, and an average particle diameter of 0.1 to 5 占 퐉 is used. More preferably, SiO ₂ and boron nitride having an average particle diameter of 0.5 to 2 μm are used. More preferably, 80 to 90% by weight of SiO ₂ and 10 to 20% by weight of boron nitride are mixed and used.

The filler is contained in an amount of 140 to 170 parts by weight based on 100 parts by weight of the epoxy resin. When the content of the filler is less than 140 parts by weight, there is a chip rotation problem. When the content of the filler is more than 170 parts by weight, there is a problem of solder wetting. Preferably 140 to 160 parts by weight, and more preferably 140 to 150 parts by weight.

In addition, the nonconductive paste composition according to an embodiment of the present invention further includes a thixotropic agent to control the viscosity of the composition. The sizing agent may be at least one selected from the group consisting of Wax, Thixo ST, Glycol Powder, and Powder Type Epoxy Resin.

The sizing agent is included in an amount of 0.5 to 4 parts by weight based on 100 parts by weight of the epoxy resin. If the content of the shrink agent is less than 0.5 parts by weight, there is a problem in the process due to spreading of the flux after the dispenser operation. If the shrink agent content exceeds 4 parts by weight, it spreads inside the chip when heated, There is a problem in filling. Preferably 1 to 3 parts by weight.

Further, the nonconductive paste composition according to an embodiment of the present invention may further include additives such as a coupling agent, a film smoothing agent, and a defoaming agent.

When a chip bonding process using a solder bump is performed using the nonconductive paste composition according to an embodiment of the present invention, it can be widely used in various bonding methods, and various processes of the bonding process can be integrally performed . Especially, it can be used for thermocompression bonding and laser bonding, so that a fine pitch implementation and a solder bump design provide an easy effect.

More specifically, the bonding method using the nonconductive paste composition according to the present invention is shown in FIG. As shown in FIG. 1, a semiconductor chip on which a solder bump is formed and a printed circuit board on which electrodes are formed are prepared, and a nonconductive paste composition is applied on a PCB substrate using a dispenser. A semiconductor chip on which a solder bump is formed is placed on a PCB substrate coated with a nonconductive paste composition, and the bonding area electrode and the solder are brought into contact with each other.

At this time, in the case of the nonconductive paste composition according to the present invention, the paste composition can be cured by a thermal compression method or a laser method, and at the same time reflow of the solder is possible. In the case of the thermocompression bonding method, the semiconductor chip is completely pressed on the printed circuit board by heating at a temperature of 240 to 250 ° C and applying a pressure of 1.5 to 2 bar. In the laser type, The semiconductor chip was completely pressed and bonded on the printed circuit board by irradiating the laser beam for 5 seconds.

In the bonding method using a nonconductive paste according to the present invention, since the paste acts as a flux and surrounds the solder ball and cures while filling the space between the solder balls, the fluxing process, the reflow process, and the underfill process are performed as a single process And the equipment, cost and time required for the bonding process can be drastically reduced.

In particular, it can be used for thermocompression bonding and laser bonding, and it is possible to provide a fine pitch of less than 100 μm and a nonconductive paste composition which facilitates solder bump design.

Examples and Comparative Examples

(1) Production of nonconductive paste composition

Conductive paste composition was prepared by mixing the components and the contents shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Epoxy
resin KDS-8170
(BPF) 7 7.3 7.7 10 8.8 26.8 KFR-226
(cycloaliphatic) 10 12 11 16.8 5.5 - NC-3000H
(biphenyl novolac) 7.3 7.5 8.0 7.3 11.4 - EP-156
(BPA) 2.5 - - 9.6 2 - Activator 2,2-Bis (hydroxymethyl) propionic acid 7 7 8 3 3 7 Hardener THPA 21.6 21.6 21.7 39 6 25.6 PN-23 One One - 3 5 - DICY 3 3 3 3 16 - Accelerator DA 0.3 0.3 0.3 0.3 0.3 0.3 Filler boron nitride (1 [mu] m) 5 5 5 - - 5 SiO ₂ (1 m) 35 35 35 6 40 35 Thixotropic Thixo ST 0.3 0.3 0.3 2 2 0.3 Total 100 100 100 100 100 100

(2) Thermocompression bond bonding

The nonconductive paste composition prepared in the above Examples and Comparative Examples was applied to a printed circuit board using a dispenser set at 70 ° C., heated to 250 ° C. and 2 bar pressure was applied to completely press the semiconductor chip on the printed circuit board Bonding.

(3) Laser bonding

The nonconductive paste composition prepared in the above Examples and Comparative Examples was applied to a printed circuit board using a dispenser set at 70 ° C. and irradiated with laser light for 3 seconds in a device having heat of 250 ° C. level, The semiconductor chip was completely pressed and bonded.

Experimental Example

(1) Chip Rotation

As shown in FIG. 2, a package bonded by the thermocompression bonding method or the laser bonding method was evaluated for chip rotation. An electrical signal can only be passed when the pattern of the chip's electrical signal and the pattern of the substrate coincide through the solder joint. The fact that no electrical signal flows at all means that the junction between the chip and the substrate is not properly performed. rotation. When the pad of the bottom package is not exposed, the voltage is applied. When it is not tilted, it is judged as OK when the bonding is normal, when the tilted shape is not conductive, it is determined as NG. Respectively.

(2) Solder not wetting

A voltage was applied to the package bonded by the thermocompression bonding method or the laser bonding method to determine whether the solder was normally wetted. Then, it was judged OK / NG as to whether the solder was normally wetted. . FIG. 3 is a photograph showing the measurement of the current passing through the laser bonding.

Thermocompression bonding Laser bonding Chip Rotation Solder not wetting Chip Rotation Solder not wetting Example 1 OK OK OK OK Example 2 OK OK OK OK Example 3 OK OK OK OK Comparative Example 1 NG OK NG OK Comparative Example 2 NG OK OK NG Comparative Example 3 NG NG NG NG

The features, structures, effects, and the like illustrated in the above-described embodiments can be combined and modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

Claims (10)

A nonconductive paste composition for bonding a chip and a substrate together with a solder bump for electrically connecting between a semiconductor chip and a printed circuit board (PCB)
An epoxy resin comprising at least two selected from the group consisting of bisphenol A type, bisphenol F type, aliphatic polyglycidyl type, phenol novolak type and cresol novolac type epoxy;
An amine, an amine-modified latent curing agent, an imidazole-based curing agent, a polyphenol-based curing agent and an acid anhydride curing agent;
An active agent comprising at least one member selected from the group consisting of propionic acid, adipic acid, succinic acid, palmitic acid, tetraheptanoic acid and dimethylpropionic acid;
A curing accelerator comprising at least one member selected from the group consisting of tertiary amine salts, acid anhydrides containing accelerators, and dicyandiamide;
A filler comprising at least one selected from the group consisting of SiO ₂ , TiO ₂ , AlO ₂ , AlO ₃ , Silicon Carbide, and Boron Nitride;
Wax, Thixo ST, Glycol Powder, Powder Type Epoxy Resin, and the like.
Wherein the curing agent is 90 to 100 parts by weight, the activator is 20 to 40 parts by weight, the curing accelerator is 1 to 4 parts by weight, the filler is 140 to 170 parts by weight based on 100 parts by weight of the epoxy resin, 0.5 to 4 parts by weight,
Wherein the filler has an average particle size of 0.5 to 2 占 퐉, and the bonding is laser bonding to irradiate and cure the nonconductive paste composition with a laser. delete The method according to claim 1,
The epoxy resin is a nonconductive paste composition comprising any three or more selected from the group consisting of bisphenol A type, bisphenol F type, aliphatic polyglycidyl type, phenol novolak type, and cresol novolak .
The method of claim 3,
Wherein the epoxy resin comprises 40 to 60% by weight of aliphatic polyglycidyl, 20 to 30% by weight of bisphenol F type and phenol novolak type, respectively.
5. The method of claim 4,
Wherein the curing agent comprises 80 to 90% by weight of an acid anhydride-based curing agent, 1 to 5% by weight of an amine-modified latent curing agent, and 10 to 15% by weight of polyphenol. 5. The method of claim 4,
Wherein the curing agent comprises an acid anhydride-based curing agent, an amine-modified latent curing agent, and an amine-based curing agent. The method according to claim 6,
Wherein the filler comprises 80 to 90% by weight of SiO ₂ and 10 to 20% by weight of boron nitride. delete delete delete

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